Field of the Invention
The invention relates to an electric connector including a housing to be fit into a mating electric connector, and a cylindrical hollow terminal making contact with a projecting terminal arranged in the mating electric connector when the projecting terminal is inserted into the cylindrical hollow terminal. The invention further relates to a method of fabricating the electric connector.
Description of the Related Art
There is known an electric connector including a cylindrical connector. The electric connector makes an electrical connection with a mating electric connector including a projecting terminal when the projecting terminal is fit into the cylindrical connector of the electric connector.
Even if the electric connector and the mating electric connector are fit into each other with the electric connector or the mating electric connecter is in rotation around an axis thereof, it is possible to cause an outer surface of the projecting terminal and an inner surface of the cylindrical terminal to make contact with each other.
Since the electric connector and the mating electric connector can be fit into each other even if they are in rotation around an axis thereof in any direction, it is possible to cause them to manually fit into each other in invisible condition.
The above-mentioned electric connector is used in a glow plug acting as a spark plug or a preheating plug in an engine, or is used as a connector for connecting a combustion pressure sensor to a wire harness.
FIG. 18 is a cross-section view of a glow plug connector suggested in Japanese Patent Application Publication No. 2005-207730.
The illustrated glow plug connector includes a connector casing 1001 and a fitting 1002. The connector casing 1001 includes sensor contact terminals 1011 to 1013 arranged on an inner wall of the connector casing 1001. The fitting 1002 includes a hollow tube 1003 extending coaxially with and centrally longitudinally of the fitting 1002. Contact terminals 1014 to 1016 are arranged on an outer wall of the tube 1003. The contact terminals 1014 to 1016 make contact with the sensor contact terminals 1011 to 1013, respectively, when the connector casing 1001 is fit into the fitting 1002. Within the tube 1003 is arranged a current contact 1006 which makes contact with a current contact 1005 of the connector casing 1001 when the connector casing 1001 is fit into the fitting 1002.
There is known a coaxial connector including a first electric connector having a projecting terminal, and a mating electric connector having a cylindrical connector. The first and second connectors can be fit into each other only in a predetermined direction.
FIG. 19 is a cross-sectional view of the coaxial connector suggested in Japanese Patent Application Publication No. 2012-129103.
The illustrated coaxial connector includes a female connector 1110 and a male connector 1120.
The female connector 1110 includes a female housing 1110H, a female outer terminal 1110To housed in the female housing 1110H, a female inner terminal 1110Ti arranged in the female outer terminal 1110To, and a dielectric 1110D arranged between the female outer terminal 1110To and the female inner terminal 1110Ti.
The male connector 1120 includes a male housing 1120H, a male outer terminal 1120To housed in the male housing 1120H, and a male inner terminal 1120Ti arranged in the male outer terminal 1120To.
In the coaxial connector illustrated in FIG. 19, the female housing 1110H and the dielectric 1110D are formed integral with each other, and an entirely circumferential shield for an area at which the female inner terminal 1110Ti and the male inner terminal 1120Ti make contact with other is defined by a half-cylinder of the male outer terminal 1120To and a half-cylinder of the female outer terminal 1110To.
In the coaxial connector illustrated in FIG. 19, the female inner terminal 1110Ti (a cylindrical terminal) is coaxially surrounded by the dielectric 1110D formed integrally with the female housing 1110H. Thus, the female inner terminal 1110Ti is firmly supported at an outer surface thereof by the dielectric 1110D.
In a process of integrally forming a cylindrical terminal and a housing, a cylindrical terminal is put into a cavity of a die, and then, molten resin for forming a housing is poured into the cavity. Thus, the resultant housing has the same shape as that of the cavity. When the housing is formed, it is necessary to insert a projecting terminal into the cylindrical terminal to ensure a space in an inner space of the cylindrical terminal. The space means a space in which the projecting terminal makes contact with an inner surface of the cylindrical terminal.
The above-identified Japanese Patent Application Publications are silent about steps of forming a housing. For instance, if steps of arranging a cylindrical terminal in a cavity of a die and pouring molten resin into the cavity were merely carried out, the molten resin would flow into an inner space of the cylindrical terminal, and thus, it would not be possible to ensure a space in which the projecting terminal makes contact with the cylindrical terminal.